sql中,In和where的区别
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<pre class="best-text mb-10"><span style="font-size: 16px; font-family: 宋体"><span class="baidu-highlight">SQL 语句中In 和 Where 的含义不同。<span style="font-size: 16px; font-family: 宋体">应用解释如下：<span style="font-size: 16px; font-family: 宋体">1、如需有条件地从表中选取、删除、更新数据时，使用Where；<span style="font-size: 16px; font-family: 宋体">2、In只作为Where条件子句下的一个运算符，除了In之外还有Between、Like、=、>、>=、<、<=等运算符。<span style="font-size: 16px; font-family: 宋体">下面举例说明：<span style="font-size: 16px; font-family: 宋体">1、查询名字为A和B的学生，则语句为<span style="font-family: 宋体"><span style="font-size: 16px">Select from student where name in('A','B');<span style="font-size: 16px">.......................................................................................................................<span style="font-size: 16px"><span class="con">where 后面是一个条件式，表示要找出满足这个条件的结果in 里面是个子查询或者给定的值比如 select from student where <a class="baidu-highlight" href="https://www.baidu.com/s?wd=Sn&tn=44039180_cpr&fenlei=mv6quAkxTZn0IZRqIHckPjm4nH00T1Y3rAczuHnvPjuhryubnHub0ZwV5Hcvrjm3rH6sPfKWUMw85HfYnjn4nH6sgvPsT6KdThsqpZwYTjCEQLGCpyw9Uz4Bmy-bIi4WUvYETgN-TLwGUv3EPHmdn1fvnHD" target="_blank">Sname='张三'；/查询姓名叫张三的学生的信息/select from student where <a class="baidu-highlight" href="https://www.baidu.com/s?wd=Sn&tn=44039180_cpr&fenlei=mv6quAkxTZn0IZRqIHckPjm4nH00T1Y3rAczuHnvPjuhryubnHub0ZwV5Hcvrjm3rH6sPfKWUMw85HfYnjn4nH6sgvPsT6KdThsqpZwYTjCEQLGCpyw9Uz4Bmy-bIi4WUvYETgN-TLwGUv3EPHmdn1fvnHD" target="_blank">Sname in('张三','李四')；/查询张三和李四的学生的信息/select from student where <a class="baidu-highlight" href="https://www.baidu.com/s?wd=Sn&tn=44039180_cpr&fenlei=mv6quAkxTZn0IZRqIHckPjm4nH00T1Y3rAczuHnvPjuhryubnHub0ZwV5Hcvrjm3rH6sPfKWUMw85HfYnjn4nH6sgvPsT6KdThsqpZwYTjCEQLGCpyw9Uz4Bmy-bIi4WUvYETgN-TLwGUv3EPHmdn1fvnHD" target="_blank">Sname in(select Sname from sn where Sno='001')；/查询学号是001的学生信息/<span style="font-size: 16px"> （编辑：李大同） 【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容! |